1. Field of the Invention
The present invention relates to materials used in gland packing made from expansive graphite, the gland packing made from expansive graphite made from the materials and a producing method of gland packing made from expansive graphite, and more particularly, it relates to the materials gland packing materials with producing facility in addition to sealing ability, heat resistance, chemical resistance and such properties and without causing stress relaxation made from expansive graphite, the gland packing made from expansive graphite made from the materials and producing method of gland packing made from expansive graphite.
In the specification, the term xe2x80x9ctwisting a strip laminated sheetxe2x80x9d means a movement of constructing a strip laminated sheet into a cylindrical with two parts of a strip laminated sheet that separates into axially rotate on opposite direction each other. In such case, both of twisting cylindrical so that adherence covers a linear member core, and twisting cylindrical (circular cylinder substantially without having hollow part is preferable) so that does not cover a linear member core are available.
In the specification, xe2x80x9cwinding a strip laminated sheetxe2x80x9d means a movement of constructing a strip laminated sheet into a cylindrical with a strip laminated sheet winding spirally around axis. In such case, both of twisting cylindrical so that adherence covers a linear member core, and twisting cylindrical (circular cylinder substantially without having hollow part is preferable) so that does not cover a linear member core are available.
In the specification, means the product of a tensile strength of the materials (kgf/cm2) and the cross sectional area of the materials (cm2) in case of materials resulting in a fracture.
2. Description of the Related Art
As a packing that carries out a shaft sealing of fluid apparatus, there has been a gland packing made from expansive graphite hitherto. The gland packing made from expansive graphite is packed in a room that is formed in-between a shaft and an apparatus causing, i.e., the inside of stuffing box, in order to prevent fluid from in-between the shaft and the apparatus causing. Compared with a packing material such as asbestos, the expansive graphite surpasses in hardly causing stress relaxation, lubricating ability, heat resistance, chemical resistance and such properties, but on the other hand, it has defects that its tensile strength is weak and also fragile. Thus, when constructing a sheet from expansive graphite and twist processing such sheet, there have been circumstances wherein said sheet fractures due to a big tensile force reacted thereto. From such reasons, there have been few circumstances wherein a gland packing made from expansive graphite is constructed from expansive graphite itself, and it is usually produced by reinforcing with other materials.
As a gland packing made from expansive graphite that has a reinforced structure, the following has been suggested.
For example, a gland packing made from expansive graphite wherein: a laminated sheet is constructed by laminating a cotton threaded fabric sheet on one surface of expansive graphite sheet; a strip laminated sheet is formed by cutting such laminated sheet; braiding yarn is constructed by a twist processing of such laminated sheet so that the strip laminated sheet covers a reinforcing linear member and that the expansive graphite sheet positions on the outside, and after this, such braiding yarn is braided into a gland packing made from expansive graphite sheet, is suggested.
In this example, when twist processing the laminated sheet and braiding the braiding yarn, tensile force reacts to the expansive graphite sheet. However, the expansive graphite does not fracture, because it is reinforced with the cotton threaded fabric sheet.
However, in the prior art as mentioned above, there had been some problems that follow.
That is, the tensile force of cotton linear member is not very high, in order to the cotton threaded fabric sheet to function sufficiently as a reinforcing material, it was necessary to have the sectional area of said sheet bigger. To correspond to this necessary, the width of cotton threaded fabric sheet was widened by winding the width of strip laminated sheet, in particularly, the width had been set larger than 10 mm. However, it was difficult to gain braiding yarn of good quality. This was because the flexibility of the laminated sheet gets lower as the width of thereof becomes over 10mm, causing a difficulty in a twist processing. Also, the braiding yarn gained in such way was inferior in flexibility, causing a difficulty when braiding thereof.
Further, heat loss of the cotton-threaded fabric under heat circumstance is big. Thus, the stress relaxation under heat circumstance is big, and it was difficult to save the capability of gland packing itself unless practicing tightening when the cotton threaded fabric is used as a gland packing material.
Further, the gland packing made from expansive graphite that was gained by braiding with this braiding yarn is also inferior in flexibility. If such gland packing made from expansive graphite with low flexibility was packed in the stuffing box, it might not be possible to secure sufficient sealing ability, even if the gland was bound tightly.
The present invention has invented under such actual circumstances, and aims to offer the gland packing materials made from expansive graphite, the gland packing made from expansive graphite and a producing method of gland packing made from expansive graphite, with producing facility in addition to sealing ability, heat resistance, chemical resistant and such properties and with causing no stress relaxation.
The present invention as set forth in claim 1 is a braiding yarn used in a gland packing made from expansive graphite that is gained by a pressure forming of a cord body constructed by braiding with the braiding yarn wherein: a bundle of opened carbon multifilament is laminated and unified through an adhesive layer on a surface of expansive graphite sheet; this adhesive layer is used as a reinforcing material of the strip laminated sheet consisting of the bundle of opened carbon multifilament, adhesive layer, and the expansive graphite sheet; the strip laminated sheet is winded and twisted to be filamentous as the bundle of opened carbon multifilament is positioned outside of the braiding yarn.
The present invention as set forth in claim 2 is a braiding yarn set forth in claim 1 wherein: said strip laminated sheet is winded or twisted to be filamentous so that said laminated sheet covers a reinforcing linear member.
The present invention as set forth in claim 3 is a braiding yarn set forth in claim 1 wherein: said filamentous body is constructed, and another filamentous body is constructed from a strip foil made from aluminum, aluminum alloy, nickel, nickel alloy, copper, or copper alloy so that the filamentous body covers whole said filamentous body continuously or intermittently.
The present invention as set forth in claim 4 is a braiding yarn set forth in claim 2 , wherein said reinforcing linear member constructed from at least one material from aramid resin, polytetrafluoroethylene resin, nylon resin, acrylic resin, hydroxybenzene resin or carbide resin off these, glass, metal, asbestos or a variety of ceramic.
By offering these inventions, the subjects as mentioned above are solved.